SFS-EN ISO 3741:en

Soveltamisala

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ISO 3741:2010 specifies methods for determining the sound power level or sound energy level of a noise source from sound pressure levels measured in a reverberation test room. The sound power level (or, in the case of noise bursts or transient noise emission, the sound energy level) produced by the noise source, in frequency bands of width one-third-octave, is calculated using those measurements, including corrections to allow for any differences between the meteorological conditions at the time and place of the test and those corresponding to a reference characteristic impedance. Measurement and calculation procedures are given for both a direct method and a comparison method of determining the sound power level and the sound energy level.
In general, the frequency range of interest includes the one-third-octave bands with mid-band frequencies from 100 Hz to 10 000 Hz. Guidelines for the application of the specified methods over an extended frequency range in respect to lower frequencies are given in an annex. ISO 3741:2010 is not applicable to frequency ranges above the 10 000 Hz one-third-octave band.
The methods specified in ISO 3741:2010 are suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001.
The noise source under test can be a device, machine, component or sub-assembly. ISO 3741:2010 is applicable to noise sources with a volume not greater than 2 % of the volume of the reverberation test room. For a source with a volume greater than 2 % of the volume of the test room, it is possible that the achievement of results as defined in ISO 12001:1996, accuracy grade 1 (precision grade) is not feasible.
The test rooms that are applicable for measurements made in accordance with ISO 3741:2010 are reverberation test rooms meeting specified requirements.
Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3741:2010, for measurements made in limited bands of frequency and for A-weighted frequency calculations from them. The uncertainty conforms to ISO 12001:1996, accuracy grade 1 (precision grade).

Tämän julkaisun valmistelusta Suomessa vastaa Metalliteollisuuden Standardisointiyhdistys ry, puh. 09 19 231 (vaihde).

Sisällysluettelo

Foreword
Introduction
1 Scope

1.1 General
1.2 Types of noise and noise sources
1.3 Reverberation test room
1.4 Measurement uncertainty

2 Normative references
3 Terms and definitions
4 Reference meteorological conditions
5 Reverberation test room

5.1 General
5.2 Volume and shape of test room
5.3 Sound absorption of test room
5.4 Criteria for background noise
5.5 Atmospheric temperature, humidity and pressure

6 Instrumentation and measurement equipment

6.1 General
6.2 Calibration

7 Definition, location, installation, and operation of noise source under test

7.1 General
7.2 Auxiliary equipment
7.3 Noise source location
7.4 Installation and mounting conditions
7.5 Operation of source during test

8 Measurements in the reverberation test room

8.1 General
8.2 Initial location of the noise source under test
8.3 Microphone positions
8.4 Measurement of sound pressure levels
8.5 Measurement of single event time-integrated sound pressure levels
8.6 Measurement of sound pressure levels from the reference sound source for the comparison method
8.7 Measurement of reverberation time
8.8 Measurement of meteorological conditions

9 Determination of sound power levels and sound energy levels

9.1 Determination of sound power levels
9.2 Determination of sound energy levels
9.3 A-weighted sound power level and sound energy level

10 Measurement uncertainty

10.1 Methodology
10.2 Determination of σomc
10.3 Determination of σR0
10.4 Typical upper bound values of σR0
10.5 Total standard deviation σtot and expanded measurement uncertainty, U

11 Information to be recorded

11.1 General
11.2 Noise source under test
11.3 Test environment
11.4 Instrumentation
11.5 Acoustical data

12 Test report

Annex A Guidelines for the design of reverberation test rooms (informative)
Annex B Guidelines for the design of rotating diffusing vanes (informative)
Annex C Reverberation test room qualification procedure for the measurement of broad-band sound (normative)
Annex D Reverberation test room qualification procedure for the measurement of discrete-frequency components (normative)
Annex E Extension of frequency range to frequencies below 100 Hz (informative)
Annex F Calculation of octave band sound power levels and sound energy levels, A-weighted sound power levels and A-weighted sound energy levels from one-third-octave band levels (normative)
Annex G Guidelines on the development of information on measurement uncertainty (informative)

Bibliography

Näytä kaikki

Foreword
Introduction
1 Scope

1.1 General
1.2 Types of noise and noise sources
1.3 Reverberation test room
1.4 Measurement uncertainty

2 Normative references
3 Terms and definitions
4 Reference meteorological conditions
5 Reverberation test room

5.1 General
5.2 Volume and shape of test room
5.3 Sound absorption of test room
5.4 Criteria for background noise
5.5 Atmospheric temperature, humidity and pressure

6 Instrumentation and measurement equipment

6.1 General
6.2 Calibration

7 Definition, location, installation, and operation of noise source under test

7.1 General
7.2 Auxiliary equipment
7.3 Noise source location
7.4 Installation and mounting conditions
7.5 Operation of source during test

8 Measurements in the reverberation test room

8.1 General
8.2 Initial location of the noise source under test
8.3 Microphone positions
8.4 Measurement of sound pressure levels
8.5 Measurement of single event time-integrated sound pressure levels
8.6 Measurement of sound pressure levels from the reference sound source for the comparison method
8.7 Measurement of reverberation time
8.8 Measurement of meteorological conditions

9 Determination of sound power levels and sound energy levels

9.1 Determination of sound power levels
9.2 Determination of sound energy levels
9.3 A-weighted sound power level and sound energy level

10 Measurement uncertainty

10.1 Methodology
10.2 Determination of σomc
10.3 Determination of σR0
10.4 Typical upper bound values of σR0
10.5 Total standard deviation σtot and expanded measurement uncertainty, U

11 Information to be recorded

11.1 General
11.2 Noise source under test
11.3 Test environment
11.4 Instrumentation
11.5 Acoustical data

12 Test report

Annex A Guidelines for the design of reverberation test rooms (informative)
Annex B Guidelines for the design of rotating diffusing vanes (informative)
Annex C Reverberation test room qualification procedure for the measurement of broad-band sound (normative)
Annex D Reverberation test room qualification procedure for the measurement of discrete-frequency components (normative)
Annex E Extension of frequency range to frequencies below 100 Hz (informative)
Annex F Calculation of octave band sound power levels and sound energy levels, A-weighted sound power levels and A-weighted sound energy levels from one-third-octave band levels (normative)
Annex G Guidelines on the development of information on measurement uncertainty (informative)

Bibliography

Tuoteryhmä(t)

17.140.01 Akustiset mittaukset ja meluntorjunta yleensä »

Sidokset

Velvoittavat viittaukset

IEC 60942:2003
IEC 61183:1994
IEC 61260:1995

IEC 60942:2003
IEC 61183:1994
IEC 61260:1995
IEC 61672-1:2002
ISO 12001:1996 Acoustics -- Noise emitted by machinery and equipment -- Rules for the drafting and presentation of a noise test code
ISO 3382-2:2008 Acoustics -- Measurement of room acoustic parameters -- Part 2: Reverberation time in ordinary rooms
ISO 5725-1:1994 Accuracy (trueness and precision) of measurement methods and results -- Part 1: General principles and definitions
ISO 5725-1:1994/Cor 1:1998
ISO 5725-2:1994 Accuracy (trueness and precision) of measurement methods and results -- Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method
ISO 5725-2:1994/Cor 1:2002
ISO 5725-3:1994 Accuracy (trueness and precision) of measurement methods and results -- Part 3: Intermediate measures of the precision of a standard measurement method
ISO 5725-3:1994/Cor 1:2001
ISO 5725-4:1994 Accuracy (trueness and precision) of measurement methods and results -- Part 4: Basic methods for the determination of the trueness of a standard measurement method
ISO 5725-5:1998 Accuracy (trueness and precision) of measurement methods and results -- Part 5: Alternative methods for the determination of the precision of a standard measurement method
ISO 5725-5:1998/Cor 1:2005
ISO 5725-6:1994 Accuracy (trueness and precision) of measurement methods and results -- Part 6: Use in practice of accuracy values
ISO 5725-6:1994/Cor 1:2001
ISO 6926:1999 Acoustics -- Requirements for the performance and calibration of reference sound sources used for the determination of sound power levels
ISO/IEC Guide 98-3:2008 Uncertainty of measurement -- Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)

Tekninen komitea

CEN/TC 211 Acoustics »

Direktiivi

98/37/EC Koneturvallisuus
2006/42/EC Koneturvallisuus

http://ec.europa.eu »

Vahvistuspäivä

01.11.2010

Julkaisupäivä

19.11.2010

Painos

3

Sivumäärä

66

Julkaisun kieli

englanti